Breech-block-actuating gear for ordnance.



A. T. DAWSON & G. T. BUGKHAM. BREECH BLOCK AGTUATING GEAR FOR ORDNANGE. APPLICATION FILED AUG. 11. 1911.

1,074,842, Patented Oct. 7, 1913.

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UNITED STATES PATENT @FFTQE.

ARTHUR TREVOR DAWSON AND GEORGE THOMAS BUCKI-IAM, OF WESTMINSTER, LON- DON, ENGLAND, ASSIGNORS TO VICKERS LIMITED, OF VIESTMINSTER, ENGLAND.

BREECI-I-BLOGK-ACTUATING GEAR FOR ORDNANCE.

Application filed August 11, 1911.

To all whom, it may concern:

Be it known that we, Sir ARTHUR TREVOR DAWSON, knight, and Gnonen THOMAS BUCKHAM, both subjects of the King of Great Britain, residing at Vickers House, Broadway, Westminster, in the county of London, England, have invented certain new and useful Improvements in Breech- Block-Actuating Gear for Ordnance, of which the following is a specification.

This invention relates to breech block actuating gear for ordnance, particularly for guns of the semi-automatic type that can be readily converted into quick firing guns. In guns of this kind the breech block is adapted to slide transversely across the breech opening by means of an actuating crank mounted on a spindle carried by the gun, the said spindle being provided at one end with an external cam and at the other end with an actuating hand lever. When the gun is working semi-automatically the said cam is operated by a pawl hinged to the gun mounting so that during the return movement of the gun after recoil the pawl actuates the cam and angularly displaces the spindle to move the block into the open position. It is retained in this posit-ion by the extractor until the latter is released in introducing a fresh cartridge into the gun, whereupon the block moves into the closed position by the action of a spring. hen the gun is acting as a quick firer, the said pawl is set into a position in which it can not actuate the said cam, and the aforesaid spindle is operated manually by the actuating hand lever. The said spring is generally arranged to act also as a buffer for the block and to cause it to slightly rebound when opened in order to bring it into a position to prevent the cartridge case from becoming displaced when the gun is loaded at large angles of elevation.

According to our invention we provide the actuating spindle at its end adjacent to the hand lever with a toothed segment which engages with a rack contained within a case or cavity forming part of the said hand lever. The said rack is under the influence of a spring which is preferably of the helical type and bears at one end against the rack and at the other end against an adjustable plug or sleeve screwed into the outer end of the case. The end of the actuating spindle remote from that carrying I Specification of Letters Patent.

Patented Oct. 7, 1913.

Serial No. 643,578.

the toothed segment is provided with the cam for cooperating with the hinged pawl in the usual manner.

According to a modification in order to enable the said spring to operate as a bufier in opening the breech by hand and cause the block to rebound in opening so that the said block will serve as a cartridge retainer as 1S usual in this kind of breech mechanism, we employ a member carried by the spring case which member controls the actuating spring and is adapted to engage with a fixed stop as the hand lever approaches the fully open position.

In order that the said invention may be clearly understood and readily carried into effect we will describe the same more fully with reference to the accompanying drawings, in which Figure l is an elevation, Fig. 2 a plan, and Fig. 3 a section taken approximately on the line 11 of Fig. 1, showing one constructional form of the invention. Fig. 4 is an elevation and Fig. 5 a section taken approximately on the line 22 of Fig. 4:, showing a modified constructional form of the invention. Fig. 6 is a vertical section taken approximately along the axis of the actuating spindle of Fig. l or Fig. 4. Fig. 7 is a cross-section on the line 33 of Fig. 6 showing the cam. Fig. 8 is a side elevation, Fig. 9 a plan and Fig. 10 an end elevation showing the hinged pawl (which forms no part of our present invention) and the manner of setting the same into its inoperative position when the gun is working as a quick firer.

A is the breech end of the gun, B the breech actuating handlever, B the spring case containing the actuating spring 13 C the block actuating spindle, C" the toothed segment, C the cam and D the hinged pawl adapted to engage therewith.

The spring case B is made integral with the hand lever B, the handle B of the latter being provided with a spring catch 1) adapted to engage with a part of the gun when said hand lever is in the breech closed or closing position, the said hand lever being thereby restrained from moving until the catch is released by grasping the handle of the hand lever as is well understood. The upper end of the spindle C carries the toothed segment C" which engages with the short rack D which is slidably mounted in the case B. The helical spring B bears at one end against the said rack and at the other against the end; of the adjustable screwed plug 6 WVhen the gun is to work semi-automatlcally the aforesaid pawl D operates upon the cam C on the actuating spindle G in the usual manner and as the hand lever 13v is restrained from moving by the catch Z), the actuating spindle G will revolve and, through the intervention of the toothed segment G", will move the rack D in a direction to compress the spring B within the case B that forms part of the hand lever B, as the block assumes the open position. The re turn movement of the block is effected by the reaction of the spring B on the actuating spindle C through the rack D. and the toothed segment C". For the first round the mechanism is opened by hand, the hand lever B being then returned to its closed position in which the catch 79 engages with its pocket in the gun A. As the block is now held open by the, extractors the spring B 1s fully compressed ready to close the breech when the extractors are released by the ac tion of loading.

When the gun is to work as a quick firer, the said pawl D is set into its; inoperative position relatively tothe cam C by any suitable means such as a change over switch comprising in the example shown by Figs. 8, 9 and 10 a transversely slotted rotary pin d having an operating arm d at one. end. lgVhen this rotary pin is turned into a position in which the solid or unslotted portion lies against the pawl D the latter will be retained in a position in which it will not o-peratively engage with the cam G. The breech block can then be moved into its open position by the hand lever Band the connection existing between it and; the actuating spindle O, through the spring case B, the

rack D and the toothed segment 0*, the said rack occupying a position with its outer end abutting against the case B as shown. in Figs. 3 and 5. During the'closing of the breech the pressure of the spring B? maintains the rack D in its relationship to the pinion C and is 0;E sufficient strength to, rotate the spindle C and close the breech.

In the modification shown in Figs. i and 5,, the spring case B is provided with a twoarmed lever B pivoted thereto. One arm, 6 engages with a plunger 6 which is loosely mounted in the adjustable, threaded plug 5 and} supports the rear end of the spring B The other arm 6* has a projection Z2 which is adapted to engage with a stop or depression '6 in the gun as the hand lever" approaches the fully open position. The re sult of this engagement with the saidv d8: pression b. is to cause the spring B to become compressed: by the arm 6 acting on the plunger 6 wherebythe buffer effect is obtained and the actuating spindle C caused to, slightly move in the reverse direction to bring about a slight return movement of the block so that it can act to retain the cartridge in place during the loading operation as aforesaid.

By means of our improvements the change from semi-automatic to quick fire is effected without the necessity of employing any change over gear (with the exception of placing the hinged pawl out of action) furthermore when the gun is working as a quick firer the mechanism is not operated against the pressure of the actuating'spring.

Although we have shown our invention applied to a gun having a transversely sliding breech block, we wish it to be understood that we do not wish to limit ourselves to this type of gun, as our improvements are equally applicable to breech screw mechanism working semiautomatica.lly.

' hat we claim and desire to secure by Letters Patent of the United States is 1. In breech block actuating gear, the combination with the actuating spindle and its hand lever, of a toothed member on said spindle, a reciprocatory spring controlled toothed member carried by the hand lever and gearing with the first-mentioned mem her.

2. In breech block actuating gear, the combination with the actuating spindle, and its hand lever, of a toothed segment on the said spindle, and a spring controlled rack carried by the said hand lever and gearing with the toothed segment. 7

3. In breech block actuating gear, the

combination with the actuating spindle, and

its hand lever, of a toothed segment on the gsaid spindle, and a spring controlled rack jconta ned 1n a cavity in the hand lever and 1 gearing with the toothed segment.

4.1151 breech block actuating gear, the

Ecornbination with the actuating spindle and its hand lever, of a toothed segment on one end of the spindle, a cam on the other end of the spindle, an external pawl adapted to en gage with said cam and a spring controlled rack carried by the said hand lever and gearing with the toothed segment.

7 5,. In breech block actuating gear, the combination with the actuating spindle and its hand lever, of a toothed segment on one end of the spindle, a cam on the other end of the spindle, an external pawl adapted to engage with said cam, and a spring controlled rack contained in a cavity in the hand lever and gearing with the toothed segmen 6. In breech block actuating gear, the combination with the actuating spindle and its hand lever, of a toothed segment on one end of the spindle, a cam on the other end of the spindle, an external pawl adapted to engage with the said cam, a rack contained in a cavity in the hand lever and gearing with the toothed segment, a plug closing the said cavity and a spring disposed between the said plug and the rack.

7. In breech block actuating gear, the combination with the actuating spindle and its hand lever, of a toothed segment on one end of the spindle, a cam on the other end of the spindle, an external pawl adapted to engage with said cam, a catch carried by the hand lever and adapted to engage with a part of the gun, a rack contained in a cavity in the hand lever and gearing with the toothed segment, a plug closing the said cavity and a spring disposed between the said plug and the rack.

8. In breech block actuating gear, the combination with the actuating spindle and its hand lever, of a toothed segment on the said spindle, a rack carried by the hand lever and gearing with the toothed segment, a spring controlling the said rack, a member carried by the hand lever and cooperating with the spring, and a fixed stop with which the member engages as the hand lever approaches the fully open position.

9. In breech block actuating gear, the combination with the actuating spindle and its hand lever, of a toothed segment on the said spindle, a rack carried by the hand lever and gearing with the toothed segment, a spring controlling the said rack, a two armed lever carried by the hand lever, a plunger in contact with the spring and with one arm of the said lever and a fixed stop with which the other arm of the lever is adapted to engage.

In testimony whereof we aflix our signatures in presence of two witnesses.

ARTHUR TREVOR DAWSON. GEORGE THOMAS BUOKHAM. Witnesses:

HENRY KING, J NO. R. CAsWnLL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

